Europäisches Patentamt *EP001541579A1* (19) European Patent Office Office européen des brevets (11) EP 1 541 579 A1 (12) EUROPEAN PATENT APPLICATION published in accordance with Art. 158(3) EPC (43) Date of publication: (51) Int Cl.7: C07H 15/203, A61K 31/7028, 15.06.2005 Bulletin 2005/24 A61P 11/00, A61P 11/06, A61P 11/08, A61P 43/00, (21) Application number: 03760921.1 C07H 15/18 (22) Date of filing: 20.06.2003 (86) International application number: PCT/JP2003/007868 (87) International publication number: WO 2004/000863 (31.12.2003 Gazette 2004/01) (84) Designated Contracting States: (72) Inventors: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR • YAMASHITA, Shinya, HU IE IT LI LU MC NL PT RO SE SI SK TR c/o Nippon Suisan Kaisha, Ltd. Designated Extension States: Hachioji-shi, Tokyo 192-0906 (JP) AL LT LV MK • TAKEO, Jiro, c/o Nippon Suisan Kaisha, Ltd. Hachioji-shi, Tokyo 192-0906 (JP) (30) Priority: 20.06.2002 JP 2002180238 • OKITA, Takaaki, c/o Nippon Suisan Kaisha, Ltd. Hachioji-shi, Tokyo 192-0906 (JP) (71) Applicant: Nippon Suisan Kaisha, Ltd. Tokyo 100-0004 (JP) (74) Representative: VOSSIUS & PARTNER Siebertstrasse 4 81675 München (DE) (54) PRODURG, MEDICINAL UTILIZATION THEREOF AND PROCESS FOR PRODUCING THE SAME (57) A prodrug utilizes an enzyme whose enzymatic example of the drug, a bronchodilator can be mentioned activity is different in between the target site of the drug and as the example of the enzyme, a glycosidase (for and the site to express side effects, the prodrug having example, β-glucuronidase) can be mentioned. Further- a substituent cleavable with the enzyme and being ac- more, the substituent is, for example, a glycosyl group tivated by cleaving the substituent with the enzyme. As composed of a monosaccharide or an oligosaccharide. the target site of the drug, for example, a respiratory or- Use of the enzyme enables reducing the side effects of gan can be mentioned and as the site to express side a drug of the type whose target site is different from the effects, for example, the heart can be mentioned. As the site to express side effects. EP 1 541 579 A1 Printed by Jouve, 75001 PARIS (FR) EP 1 541 579 A1 Description TECHNICAL FIELD 5 [0001] The present invention relates to a produrg which can reduce the side effects of the drug by utilizing an enzyme whose enzymatic activity has a difference in between the target site of the drug and the site to express side effects. BACKGROUND ART 10 [0002] A number of so-called sugar substituent-bonded prodrugs have been studied. Their major object is to improve the solubility of the difficultly soluble parent compounds and to render them nontoxic on the analogy of a glucuronic conjugate. Particularly, the latter utilizes the metabolism of the body of living. In other words, the prodrugs are designed based on the thought that undesirable side effects are reduced while allowing the parent compounds to express their effect only at the affected part on the basis of the reports that the activities of sugar cleavable enzymes such as β- 15 glucuronidase and β-glucosidase in the cancer cell and the inflammatory cell are increased. Their details will now be explained below. [0003] Research reports that the activities of several glycosidases including β-glucuronidase are accelerated in the tumor tissue are published (Fishman, Science, 105, 646-647, 1947, Fishman and Anlyan, Cancer Res., 7, 808-814, 1947, and Bollet et al., J. Clin. Invest., 38, 451, 1959). With other disorders, it is reported that in an asthmatic patient 20 the β-glucuronidase activity in the alveolar lavage fluid (BALF) by the liberation of β-glucuronidase from the alveolar macrophage and the mastocyte trends to be accelerated (Tonnel et al., Lancet, 8339, 1406-1408, 1983 and Murray et al., N. Engl. J. Med., 315, 800-804, 1986), and further it is reported that the β-glucuronidase and N-acetyl-D-glucosami- nidase activities are accelerated in the synovial fluid of a rheumatic patient (Stephens et al., J. Rheumatol., 2, 393-400, 1975), and the β-glucuronidase activity in the serum of an AIDS patient is high compared to the healthy individual and 25 the like (Saha et al., Clin. Chim. Acta., 199, 311-316, 1991), and thus in the affliction of various types of disorders the acceleration of the activity of a glycosidase or the extracellular liberation of a glycosidase is suggested. Of these glycosidases, β-glucuronidase of an especially noted enzyme is an enzyme which hydrolyzes a β-glucuronide to catalyze the reaction to liberate D-glucuronic acid, and it is reported that β-glucosidase is present in a wide range of organs such as the liver, the lungs, the spleen, and the kidneys or inflammatory cells such as macrophages and 30 eosinophils (Hayashi, J. Histochem. Cytochem., 15, 83-92, 1967 and Conchie et al., Biochem. J. 71, 318-325, 1959). [0004] In the chemotherapy of cancers an important problem is to reduce the toxicity against the normal tissue or the normal cell other than the tumor. In order to solve this problem, a number of antitumor agents which specifically act on the tumor tissues were developed but the expected reduction of side effects has not been found in any of them. [0005] De Duve took note of a hydrolase in the lysosome containing a glycosidase in the tumor tissue and proposed 35 the concept of the chemotherapy by the prodrug of an antitumor agent to be activated by the hydrolysis with the hy- drolase and the enzyme (Biological approaches to cancer chemotherapy, 101-112, Academic Press, Inc., 1961). Connors and Whisson showed in the experiment using mice a high correlation between the antitumor effect of aniline mustard of an antitumor agent and the β-glucuronidase activity of the tumor cell (Nature, 210, 866-867, 1966). Sweeny et al. published a theory about the mechanism of the action of mycophenolic acid of an antitumor agent that mycophe- 40 nolic acid is glucuronidated in an organ and the resulting glucuronic conjugate is hydrolyzed with β-glucuronidase in the tumor tissue to form an active form of mycophenolic acid which exhibits the antitumor effect (Cancer Res., 31, 477-478, 1971). Young et al. conducted a clinical test with a cancer patient on the hypothesis that aniline mustard of an antitumor agent is glucuronidated within the body and the resulting glucuronic conjugate exhibits the antitumor effect by the hydrolysis in the cancer tissue as in the case of mycophenolic acid of an antitumor agent but a sufficient corre- 45 lation between the antitumor effect and the enzymatic activity was not recognized (Cancer, 38, 1887-1895, 1976). Baba et al. reported that with the use of a mouse breast cancer model, a glucuronic acid derivative of 5-fluorouracil of an antitumor agent is intravenously administered to exhibit an inhibition (Gann, 69, 283-284, 1978). However, the sugar derivative prodrugs of these antitumor agents are generally insufficient in the hydrolysis in the target site, and accord- ingly satisfactory results of their clinical test have not been obtained. 50 [0006] Next, an approach was made that a product obtained by bonding a tumor-specific antibody to various enzymes was administered beforehand and a prodrug which was to be converted to the active form by the cleavage with these enzymes is used. This is called ADEPT (antibody-directed enzyme prodrug therapy) and a number of researches and developments were done but there are problems that an exogenous antibody-enzyme composite has immunoanti- genicity and the prodrug cannot be sufficiently activated within the body of living, and thus the ADEPT has not obtained 55 success yet. [0007] Then, Bossler et al. (Br. J. Cancer, 65, 234-238, 1992) synthesized a compound through a spacer without directly bonding a sugar to an antitumor agent having low immunoanti-genicity in order for the administered prodrug having an antitumor agent-sugar derivative structure to efficiently undergo hydrolysis in the cancer cell and tried to 2 EP 1 541 579 A1 improve the above described problem. In this process they found derivatives which exhibited a sufficient effect with glycoside-spacer derivatives alone and disclosed structures of glycoside-spacer drugs as the prodrugs applicable to antiinflammatories, immunosuppressives, calcium antagonists, sympathomimetic substances and the like in addition to antitumor agents {U.S. Patent No. 5,621,002 (Family Patent: European Patent Application Publication No. 642799, 5 Japanese Patent Publication No. Hei 7-149667/1995), U.S. Patent No. 5,935,995 [Family Patent: European Patent Application Publication No. 795334, Japanese Patent Publication (Kokai) No. Hei 10-1495/ 1998], and U.S. Patent No. 5,955,100 [Family Patent: European Patent Application Publication No. 595133, Japanese Patent Publication (Kokai) No. Hei 6-293665/1994]}. [0008] In Japanese Patent Publication (Kokai) No. Hei 6-293665/1994, it is described that "the compounds are ac- 10 tivated by enzymes which in the healthy individual occur principally inside cells but which under the abovementioned pathophy- siological conditions have a local extracellular occurrence" and "The prodrugs according to the invention can be employed for all non-oncological disorders in which macrophages, granulocytes and platelets occur, especially in the activated state. In the activated state, the abovementioned cells mainly secrete intracellular enzymes which make site-specific activation of the prodrugs according to the present invention possible." 15 [0009] Further, it is described that on the basis that the substances of this citation in the case of using an antitumor agent as the active drug are not only recognized in the tumor model but also have been recognized in several inflam- matory models, they can be supposed for all disorders in which inflammatory cells participate as in tumor.